Biosynthesis
Purine metabolism involves the formation of adenine and guanine. Both adenine and guanine are derived from the nucleotide inosine monophosphate (IMP), which is synthesised on a pre-existing ribose phosphate through a complex pathway using atoms from the amino acids glycine, glutamine, and aspartic acid, as well as fused with the enzyme tetrahydrofolate.
In Saccharomyces cerevisiae (yeast), the adenine pathway converts P-ribosyl-PP into adenine through a seven-step process.
Read more about this topic: Adenine